forms of extraterrestrial intelligence

In speculating about the guises that intelligence may assume elsewhere,
it is worth remembering the diversity of intelligence that exists even on
Earth, both within and between species. This broad terrestrial spectrum
strongly suggests that among organisms that have evolved on other worlds,
and adapted to different environments and perhaps with a different biochemical
basis, there may be an even richer variety of intelligent forms, just as
extraterrestrial life in general is likely to prove surprising and novel
to us (see extraterrestrial life, variety of).
However, some aspects of intelligence may not be so different from one planet
to another. All creatures are subject to the same physical rules and, as
Carl Sagan points out in his Dragons of
Eden:1

Natural selection has
served as a kind of intellectual sieve, producing brains and intelligences
increasingly competent to deal with the laws of nature... [T]he same evolutionary
winnowing must have occurred on other worlds that have evolved intelligent
beings... I think we will find that much of their biology, psychology,
sociology and politics will seem to us stunningly exotic and deeply mysterious.
But I suspect we will have little difficulty in understanding each other
on the simpler aspects of astronomy, physics, chemistry and perhaps mathematics.

The biological evolution of intelligence is slow, although as in the 5-million-year
development of modern humans from an ape ancestor, it can undergo comparatively
rapid spurts. By contrast, it is likely that technology can dramatically
enhance intelligence over almost insignificant timescales. The human race
now appears to be on the brink of this development with the first practical
applications of brain-computer links. Once such connections are perfected
and become freely available, it is difficult to predict what levels of intelligence
a man-machine symbiosis might achieve.

The idea that sentient machines might be the ultimate product of life's
evolution has long existed in fiction. The Greek god Hephaistos is described
in the Iliad as having artificial women of gold to help him around
the house. A bronze giant, Talos, was supposed
to guard the shores around Crete. And in his witty satire Erewhon
(1872), Samuel Butler suggested that machines are evolving faster than people
because people tend and develop them. More recently, following the dawn
of electronic computers, writers such as Arthur C. Clarke
and Isaac Asimov have explored futures in
which machines, both benign and malignant, partly take over human affairs.
In view of the rapid progress made in computer technology and robotics over
the past couple of decades, it no longer seems far-fetched that artificial
intelligence may one day far exceed that of humans. Developments such
as the Internet and prototype brain-computer links suggest that some form
of part-human part-machine life-form might emerge in the not-so-distant
future. Fictional explorations of such possibilities are commonplace –
for example, Mr. Data and the Borg in Star
Trek. As time goes on, and we see the pace of our own technological
development far outstripping that of biological evolution, the conclusion
becomes compelling that if advanced extraterrestrial intelligence exists
then some of it at least may be partly artificial.2